give rename functionality

New widgets to try are (grouped) GtkClist -> Gtk{TreeView,Model}

This (small) limitation is hard to fix but since $# (the number of params)
is checked for in findsn, you can't do stuff like:
findsn -A -name "python*"
Would need to check no paths specified (I.E. like what getfpf does).

would be good to merge hardlinked files in findns
